Network backup systems process vast amounts of data between computers and storage devices often in parallel streams of data. One of the biggest challenges for ingesting multiple data streams into a backup storage system is to distribute those streams across multiple network interfaces for good performance. Link aggregation is a computer networking technique for combining or aggregating multiple network connections in parallel in order to increase throughput beyond what a single connection can sustain, and to provide redundancy in case one of the links should fail. A link aggregation group combines a number of physical ports together to make a single high-bandwidth data path, providing load sharing of data traffic among ports and improving connection reliability. The Link Aggregation Control Protocol (LACP) as defined in IEEE 802.3ad provides a method to control the bundling of several physical ports together to form a single logical channel. LACP, however, poses certain challenges. For example, it can be very difficult to install and maintain, it does not always deliver the full bandwidth of all interfaces, any changes require taking interfaces offline for configuration, and it is very sensitive to network errors. An additional disadvantage of LACP is that it is limited to only one IP (Internet Protocol) address. This requires a tedious configuration operation at every network hop.
Another mechanism to accommodate the ever increasing amounts of data and number network nodes is Network Address Translation (NAT), which is a methodology that remaps one IP address space into another by modifying network address information in IP datagram packet headers while they are in transit across a router. This mechanism has become important in conserving global address space allocations in the face of address exhaustion concerns. NAT allows a single device to act as an agent between the Internet and a local network, so that only a single, unique IP address is required to represent an entire group of computers. In this manner, an entire network (e.g., wide or local area network) can be mapped to a single IP address.
To optimize network performance, load balancing techniques are often used to balance client connections over multiple server interfaces that exist within a a NAT environment. For example, certain interface grouping methods have been developed to perform IP redirects, load balancing and fail-over to provide this functionality over across NAT networks.
However, present load balancing solutions are not necessarily compatible or at least optimal with LACP networks. This is because only one IP address is used with LACP and this requires tedious configuration operations at each network hop or node.
Therefore, there is generally a need for improved systems and techniques of link aggregation especially in relation to load balancing and failover operations in a networked-based data backup system. There is a further need for providing load balancing over multiple IP addresses across a NAT network with a simple configuration procedure.
The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions. EMC, Data Domain, Data Domain Replicator, and Data Domain Boost are trademarks of EMC Corporation.
Multi-Path distribution, load balancing and failover for interface groups is hereafter referred to as the ifgroup method, where “ifgroup” may refer to an interface group.